Customary International Law, Sovereign Consent, and the Juridical Singularity

Most people think of international law as a set of rules written down in treaties. That framing misses something important. Treaties derive their force from a deeper substrate: the customary practice of states and the shared recognition that certain conduct is legally required. Understanding that substrate changes how you read every treaty, every institutional charter, every claim that some norm is binding. This course starts there, with sovereignty and the two-element theory of customary law, and builds outward. The middle section takes up treaty-making freedom and lawful modification. The central question is this: if collective state consent is the decisive source of legal authority, what exactly can states do with that authority? The doctrinal answer is more expansive than most introductory treatments suggest. Subsequent agreements can modify earlier ones. Jus cogens norms have historically shifted. Institutional structures can be succeeded. The course works through each of these mechanisms with precision, using real doctrinal examples rather than hypotheticals. The final unit introduces the juridical singularity framework, a theory of how treaty-chain mechanics and network-based territorial scope could, in principle, produce the lawful consolidation of plural sovereignty into a single juridical entity. The State Succession Deed 1400/98, a 1998 instrument concerning the former NATO property at the Turenne Barracks in Zweibrücken, serves as the primary case study. Students analyse it provision by provision using the tools built in the preceding units. Whether or not you find the framework persuasive, working through it sharpens your ability to read complex treaty structures and trace legal consequences across interconnected instruments.